The country's top tax official is to retire next summer.
Dave Hartnett, head of HM Revenue and Customs (HMRC), was forced into an apology to 1.4 million people facing surprise tax bills in September last year.
The HMRC permanent secretary said he was "deeply sorry" that taxpayers were being asked to pay back an average £1,428.
His apology was issued after he caused fury by initially insisting the authorities were not to blame and declaring: "I'm not sure I see a need to apologise."
Meanwhile HMRC was accused of giving Goldman Sachs a deal that waived £10 million of interest on a £30 million bill from a failed tax avoidance scheme on bankers' bonuses.
Mr Hartnett, 60, is said to have personally sealed the agreement with a Goldman executive last November, after being advised by an official that there was a "legal impediment" to charging interest.
He told the powerful Commons Public Accounts Committee that a HMRC official lost their bonus following the blunder.
Lin Homer will be the next chief executive of HMRC after Lesley Strathie stepped down last month on health grounds.
Ms Homer, who is currently permanent secretary at the Department for Transport, said: "Dave is widely recognised as a tax leader at home and abroad, and has secured billions in tax for the UK that would otherwise have been lost through avoidance, evasion and fraud."